Apparatus for forming a continuous assembly of envelopes or the like

ABSTRACT

Apparatus for assembling envelopes into a continuous web having removable perforate margins characterized by improvements in: apparatus for feeding envelopes from a supply stack; preventing application of adhesive to undesired zones in the event of absence of an envelope in a spaced series of same; varying the length of adhesive strips applied adjacent edges of the envelopes; changing the angular direction of feed of the envelopes where they are collated or secured together in overlapping relationship; varying the position of the collating station to accommodate envelopes of varying height; optional features include collating the envelopes on a previously perforated carrier web; and, applying reinforcing strips to the edges of the web when the overlap is relatively small and strengthening of the web at such zones is desired.

United States Patent 1191 Sutton June 26, 1973 4] APPARATUS FOR FORMINGA 2,690,102 9/1954 Halahan 93/61 AC cou'rmuous ASSEMBLY OF ENVELOPES g aoussaye..... OR THE LIKE 3,579,947 5/1971 Kalman 93/36 MM [75] Inventor:Charles 0. Sutton, Phoenix, Ariz. 3,387,542 6/1968 Gartner 93/l.1 X3,564,983 2/1971 Grimm 93/369 X [73] Asslgnw l Denver, 3,630,125 12/1971Helm 93/36 MM Colo- 3,635,128 1/1972 Dohnazik 93/36 MM [22] Filed: Dec.21, 1970 Primary Examiner-Andrew R. Juhasz PP 99,954 Attorney-Sheridan,Ross & Burton 521 US. (:1. 93/61 R, 118/210, 156/552 [571 ABSTRACT [51]Int. Cl B311, 1/06, B316 1/96 App s for mbling n lope in a n in u [58]Field of Search 93/36 MM, 369, 61-63 M, web having removable perforatemargins characterized 93/93 C by improvements in: apparatus for feedingenvelopes from a supply stack; preventing application of adhesive [56]References Cited to undesired zones in the event of absence of an enve-UNITED STATES PATENTS lope in a spaced series of same; varying thelength of adhesive strips applied adjacent edges of the envelopes; atchanging the angular direction of feed of the envelopes 3 1 6/1961 93/61A where they are collated or secured together in overlap- 3,43g 3 0 4 99 W d ff 93/63 M ping relationship; varying the position of thecollating 3,391,673 7/1968 Knapp 93/62 X station to accommodateenvelopes of varying height; 3,429,238 2/1969 Lenk 93/61 AC optionalfeatures include collating the envelopes on a 3,506,472 4/1970 'de 93/36M previously perforated carrier web; and, applying rein- Wensler forcingstrips to the edges of the web when the ov'erlap fi 93/61 AC isrelatively small and strengthening of the web at such 28479l5 241958zones is desired. 7 2,969,003 7 9 Claims, 4 Drawing Figures Pmmmwm maINVFN 7 OH CHARLES o surrorv flwm, 72min 00oF Lnooo ATTORNEYS om Nm 1APPARATUS FOR FORMING A CONTINUOUS ASSEMBLY OF ENVELOPES OR THE LIKE ofoverlapped items, feed the web through a high speed computer-printer inwhich the desired printing is applied, and subsequently separate theitems prior to mailing. The U.S. patent application of T. W. Alton, Ser.No. 608,631, filed Jan. 11, l967, now US. Pat. No. 3,547,343,exemplifies a web of the type referred to and the U.S. patentapplication of T. W. Alton, Ser. No. 727,776, filed May 8, 1968, nowU.S.' Pat. No. 3,565,728 exemplifies improvements in method andapparatus for assembling items,.such as envelopes, into a continuous webof overlapped, or shingle-like items. The web is then wound onto a reeland, as will be understood, the web is subsequently fed from the reelthrough the printer, after which the items are separated and are readyfor mailing. If the itemsare envelopes with sealable flaps, these may besealed at a desired station during the processing.

U.S. Pat. No. 3,565,728 discloses, briefly, an envelope supply hopper,vacuum transfer rolls for individually feeding the envelopes to anendless conveyor in spaced relationship, a subsequentadhesive applyingstation where strips of adhesive of desired length are applied to themargins of the envelopes, after which they are overlapped a distancecorresponding to the lengths of the adhesive strips and thence pressedtogether, forming the web.

SUMMARY OF THE INVENTION The present invention probably relates mostclosely to U.S. Pat. No. 3,565,728 and provides certain improvementsthereover which fulfill the exemplary objectives to follow:

Provides a feed hopper in which the envelopes of the supply are disposedon their edges in an upstanding arrangement and maintaining sucharrangement at an optimum angle to be transferred to vacuum wheels.

Provides an adjustment in the timing of adhesive ap-. plying rolls withrespect to the linear movement of an envelope across the rolls toproduce various desired lengths of the adhesive strips.

Provides an upwardly inclined conveyor which moves an envelope, withadhesive on same, at an upwardly inclined angle from which it isdeposited on a horizontally movable envelope ahead of same after whichit moves between the nips of pinch rolls, applying securing pressure tothe adhesive.

Provides adjustment for the pinch or collating rolls so that envelopesof various heights may be secured together or collated.

Provides a novel feed of margin tapes or an envelope BRIEF DESCRIPTIONOF THE DRAWING of FIG. 1 being omitted;and

FIG. 3 is a schematic side elevation of a portion of FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS General Description and Operation.Referring now to the drawing and first to FIGS. 1 and '2, the subject ofthe invention comprises, in general; an envelope supply station whichcontains a stack of envelopes l2 resting on their lower edges; a pair ofsuction transfer wheels 14,14; a pair of endless transfer belts 16,16;endless conveyor chains 18,18, having carrier web to the envelopes aheadof the pinch rolls.

- The foregoing objectives are exemplary, only, and

further objectives and salient features will become more apparent fromthe detailed description to follow, the appended claims, and theaccompanying drawing to now be briefly described.

spaced envelope conveying lugs 20 carried thereby; a pair of adhesiveapplying rolls 22,22; transfer rolls 24; pressurizing or pinch rolls26,26; pairs of matchedpe'rforating punch wheels 28,28a; pairs ofmatched feed pinwheels 30,30a; and pairs of rotary knives 32,324.

In the general operation of the parts just described,

suction wheels 14 pick up the foremost envelope 12 I from the supply 10and convey it to the lower runs of transfer belts 16 which transfer itto endless chain conveyor 18, the spaced lugs 20 on which move theenvelopes in predetermined spaced relation across the adhesive applyingrolls 22. As the individual envelopes leave the chain conveyor they passbetween transfer rolls 24 and are sequentially deposited in overlappingrelation on the envelope next ahead of same. The overlapped adhesivecoated area is then pressurized against the envelope ahead of it and onwhich it overlaps and the envelopes thence all travel as a continuousconnected web through the remainder of the apparatus. At a subsequentstation, spaced perforations are formed in the margins of the web byperforating punch wheels 28,28a. Feed pin wheels 30,30a then engage theperforations and feed opposite edges of the web between rotary knives32,32a which trim narrow strips from the opposite margins of the web toprovide a uniform width of same. Thereafter, the web may be processed inconventional manner, through printing apparatus, it being understoodthat after printing, the perforate margins are removed to separate theweb into individual envelopes. As hereinafter referred to, the-height ofan envelope will be considered as its dimension in the direction of itsmovement or along its side edges or margins and its width as itsdimension in a direction normal thereto. The various components justdescribed will now be described in greater detail.

Supply Station The supply station or feed hopper 10 comprises adownwardly inclined platen 34 which is mounted for vertical adjustmentrelative to the suction wheels 14. as indicated by a doublehead arrowtherebeneath to thereby position envelopes of varying height in optimumposition relative to the suction apertures 36in such wheels, the latterbeing of conventional construction as understood in the paper conveyingart. The optimum position is with the foremost envelope disposedsubstantially'tangential to the suction wheels so that they may wipeacross and pick up the foremost envelope. As this process continues,however, the stack begins to lean forwardly and space the foremostenvelope at a non-optimum angle relative to the suction wheels thusimpairing the feeding operation. To obviate this, a plurality of endlessbelts 38 are provided having upper runs which move across the top ofplaten 34 which are power driven, such as by motor 39, in response to asignal from a switch 40 which senses change of inclination away from theoptimum position.'Since the lower edges of the stack of envelopesrest'on these belts, forward movement of same carries the lower edgestoward the wheels and restores the stack to optimum angular positionrelative thereto. When the stack is restored to optimum position thesignal is broken and movement of the belts discontinues until receipt ofthe I next like signal. The control switch may be of any suitable typesuch as a sensitive microswitch which moves between on-off positions inresponse to relatively small variations in the angle of inclination ofthe foremostenvelope, this variation being within sufficiently smalllimits to always permit the vacuum wheels to pick up the foremostenvelope and remove it from the supply station.

Chain Conveyor This is of substantially conventional construction, suchas disclosed in U.S. Pat. No. 3,565,728, it being understood that thetwo chains 18 are driven in syncronism by sprockets 42 and lugs 20 areadjustable along the links of the chains so that a desired spacing maybe provided between successive pairs of the lugs to accommodateenvelopes of various heights.

Adhesive Station Adhesive applying rolls 22 are preferably of the hotmelt type, such as supplied by the Nordson Company of Buena Park,California, in which the adhesive is maintained in a molten state andthe wheels are provided with spaced apertures which apply theadhesive ina plurality of spaced dots which rapidly set. As best shown in FIG. 3,the side edges and adjacent margins of the envelopes pass across thewheels in spaced relation thereto, each margin being distorteddownwardly by a movable resilient finger 44 operated by an actuator 46to place the rolls into rolling contact with the envelope margins,forming dotted strips of adhesive thereon of desired length. As willsubsequently appear, it is desirable that the lengths of the adhesivestrips be adjustable. To attain this end, each wheel is provided with asegmented portion 48 of the apertures referred towhich is of an arcuatelength sufficient to transfer the longest strip of adhesive desired. Itrotates in timed relation to the linear movement of the spacing conveyorl8 and a clutch 50 is disposed therebetween which may be adjusted in anydesired phase relationship with respect to the movementof the spacingconveyor. Also, a speed ratio changer 52 is preferably disposed betweenthe clutch and thedrive source. When the clutch is positioned for thelongest length of adhesive, the segment of the wheel carrying theadhesive, contacts the envelope at one end of the segment and continuescontact to the other end of same. If a shorter length is desired,however, the phase angle of the wheel is angularly advanced by clutch 50so that when the envelope begins to register with the segment a portionof the segment has previously rotated ahead of the advancing envelopeand hence the length of the adhesive strip is only the length of theremaining portion of the segment. Otherwise stated, the clutch may be soadjusted to utilize all or only a desired portion of the ad hesivetransferring segment thereby transferring a strip of adhesive to theenvelope of any length less-than its maximum potential length. Eachwheel 22 rotates in a reservoir of molten adhesive which isautomatically maintained at constant level and suitable doctor bladesare provided to remove all'adhesive except the portion desired atsegmental portion 48. Sincethese features are conventional, they havenot been illustrated inthe interests of simplification of thedisclosure.

While the resilient hold down fingers have been illustrated anddescribed as movable to distort the envelope margins, with the adhesiverolls operated about fixed axes, it will be apparent that this may bereversed, if desired, to actuate the adhesive rolls upwardly intocontact with the envelope margins, the hold down fingers then beingfixed other than for their resilience. While this reversal of partswould normally be more complicated, it is nevertheless contemplatedwithin the scope of the claimed invention.

- Collating Station Referring again to FIG. 1, the envelopes are movingin an upwardly inclined path as they leave the spacing conveyor andcontinue such motion as they pass between the nips of transfer rolls 24.After passing between rolls 24 the assembled webmoves in a horizontaldirection. This change of direction is desirable since an envelope,about to enter the nips of rolls 26, is angularly spaced above theenvelope next ahead of it so that it may' lay onto the top of the latterin overlapping relation and, as it enters a nip, is pressurized orpinched into contact with the envelope immediately ahead thereof havinga portion therebelow. As will be understood, a I predetermined distanceof overlap occurs since the horizontal run is moving at a velocity lessthan the inclined run, these relative velocities being the same as inUS. Pat. No. 3,565,728 previously referred to. As previously alluded to,envelopes vary in height. One of the features of the collating stationis thus to provide suitable adjustment for effecting collation ofenvelopes of varying height. This is attained by mounting rolls 26 in amanner such that their positions are horizontally adjustable along thehorizontal run. If, then, envelopes of a height greater than illustratedare to be collated, rolls 26 are bodily shifted to the left (FIG. 1)which provides a sufficient space between transfer rolls 24 andcollating rolls 26 for the incoming envelopes to overlap and be laidupon the horizontally moving assembled web. Since the manner ofattaining such adjustment is a matter of mechanical expediency,variationsof which will be apparent to those skilled in the art, nospecificconstruction of such adjustment has been illustrated in theinterests of simplification of the disclosure. in an operativeembodiment, however, the collating rolls 26 are journaled on a subframeslidably mounted on the main frame and moved by rack and pinionmechanism. As willbe apparent, after positioning such 'subframe it maybe rigidly locked to the main 'framei'n any desired manner.

they arenow adhesively connected together along their side margins inoverlapping relation,forming a continuous web and uniformly spacedrelative to each other. It is important, however, that their spacing-bemaintained while passing through subsequent addressing apparatus, priorto their separation, so that suitable printing may be applied to theirfaces. Uniformly spaced perforations along their margins are thereforeemployedto cooperate with apparatus for performing such subsequentoperations, this as will be apparent, also being disclosed in U.S. Pat.No. 3,565,728. 7

The assembled web then passes between the nips of rotary punches 28,28awhich perforate the margins of I the web with timing perforations,analogous to those employed in moving picture photographic film, whichserve the purpose of timing the position of the envelopes relative toaddressing or printing apparatus. The now perforated web is engaged bypin wheels 30,30a which deliver it to rotary trimming knives 32,32a toslice off unwanted slight irregularities so that the web emerges fromthe apparatus as a collated plurality of overlapping envelopes forming aweb of uniform width. When pin wheels 30,30a are employed with punchwheels 28,28a, which is not always the case as will subsequently appear,they serve to punch out any loose perforations in the web so that theweb is devoid of such loose perforations when it emerges from theapparatus.

Optional Features Referring to FIG. 1A, which is a fragmentary portionof FIG. 1, but with added features, a-pair of tapes 56 may be fed fromsupply reels (not shown) about an idler roll 58 into the nip ofcollating rolls 26, one along each margin of the envelopes. These aredesirable when the overlap of the envelopes is small and the marginsrequire reinforcing. When this is employed, the driving clutch for theadhesive applying rolls is adjusted to apply adhesive to the entireheights of the envelopes so that they are not only secured together atthe overlap but the remainders of their heights are secured to thetapes. Normally, unperforated tapes are employed which, together withthe envelopes, are perforated when the web passes between rotaryperforating punches 28,28a.

Optionally, a carrier web 60, of substantially the same width as theenvelopes, may be similarly fed about an idler roll 62 into the nips ofthe collating rolls 26. Normally such web will be pre-perforated and, ifdesired, the envelopes may be secured to the carrier web in spacedrelationship, without overlap, to provide flexible hinges therebetweento permit the web to be fan-folded after it emerges from the apparatus.The carrier web, upon which suitable printing or coding may be applied,also serves as a permanent record, after being severed from theenvelopes which have been processed. In this modification, as with thetapes, adhesive is applied to the entire heights of the envelopes. Sincethe carrier web has been perforated prior to being fed to the apparatus,perforating punches 28,28a are not required and are either removed fromthe apparatus or moved to inoperative position.

The purpose of pin feed rolls 30,30a will now become more apparent. Whenthe perforating rolls are employed they not only perforate but theirperforating pins also form sprocket teeth for feeding the web. Pin feedwheels 30,30a, while driven in synchronism with the perforating rolls,do not serve as sole drive means, this function being performedprincipally by the perforating punch rolls. When the latter are moved toinoperative positions, however, when the carrier web is employed, pinwheels 30,30a then become the sole drive means for the web between thecollating rolls 26 and the discharge or exit end of the apparatus.

As will now be apparent, the tapes and carrier web serve somewhatdifferent purposes. The utility of the former resides principally intheir reinforcing feature Miscellaneous Features To render the apparatusversatile to process envelopes of various heights and widths, many ofits operative parts are constructed adjustable. As illustrated in FIG.2, the floor of the horizontal station, subsequent to the roll collatingstation, is formed with a central plate'64, which remains fixed, andlaterally adjustable plates 66. By moving plates 66 laterally relativeto plate 64 a floor of various widths is provided on which envelopes ofvarious widths may slide. The floor of the inclined' chain conveyor isconstructed in like manner (not shown). Starting with the right end ofFIG. 2, a sufficient number of erecting belts are provided so thatenvelopes of various widths may rest on at least several belts. Aspreviously described, the floor formed by these belts is verticallyadjustable to dispose envelopes of various heights in optimum positionto-be' picked up by the vacuum wheels, the latter being adjustable todispose same in optimum positions relative to the widths of theenvelopes. The sprockets which drive the conveyor chains are laterallyadjustable to various positions on their supporting shafts and lugs 20may be secured to selected chain links to provide requisite longitudinalspacing of the envelopes fed by same. The lateral positioning oftransfer rolls 24, collating rolls 26, punch rolls 28,28a, feedrolls30,30a and rotary knives 32,32a may also be varied for envelopes ofvarious widths.

With the exception of the erecting belts 38, which operateintermittently, all of the movable parts are interconnected by chains orgears so that they operate in synchronized timed relationship and therelative ratios of the various parts may be varied by suitable selectionof the sprockets or gears. As an example, if it is desired to increasethe overlap at the collating station, the peripheral speed of thecollating rolls 26 is decreased relative to the linear speed of theenvelopes fed thereto. Similarly, if the overlap is to be decreased, thespeed of rotation of the collating rolls is increased relative to thelinear speed of the envelopes fed thereto. The ,power source maybe avariable speed motor or may include a variable speed transmission sothat the speed of the various instrumentalities may be varied betweenvarious synchronized values, this being desirable since envelopes ofvariousheights require different speeds for optimum operation. .Variousdevices which are conventionally employed in paper processing apparatus,are employed but have been omitted in the drawing to avoid unnecessarycomplication of the disclosure.

These may include hold down fingers and various paper guiding devices tomaintain movement of the envelopes in their desired paths. An examplecomprises fixed brushes above the chain conveyor which exert a dragagainst the envelopes thereon to position them against their conveyinglugs so that they move in precise spaced relationship on the top run ofthe spacing conveyor. Also, suitable deflector or guide devices may beemployed, as desired, to constrain movement of the individual envelopes,or the assembled web, to the desired paths of motion. Pairs of anycooperating rolls may be adjusted so that both are positively rotated insynchronism or one is positively rotated and the other serves as anidler. Their axes of rotation may be adjusted relatively or one may befixed and the other resiliently urged toward the other. Materialsemployed may be selected, as desired, for their particular adaptabilityto perform their intended functions. Throughout the specification andclaims, specific reference has been made to envelopes but it is to beunderstood that, as stated in U.S. Pat. No. 3,565,728, such terminologyis meant to include, within the scope of this invention, flat typearticles generally that are to be assembled in interconnectedoverlapping form.

What is claimed is:

1. Apparatus for forming a continuous assembly of envelopes ininterconnected form, each envelope having removable margins and aleading and trailing portion, comprising:

' a. an endless conveyor for continuously moving the envelopes inpredetermined spaced relationship in a series,

b. means for applying adhesive material of desired length to theenvelope margins during their spaced movement along the endlessconveyor,

c. means for subsequently securing said envelopes together with thepreviously applied adhesive, and

d. an upstream feed station for said endless conveyor comprising;

1. a feed hopper upon which a stack of envelopes is adapted to rest ontheir lower edges and normally in a plane perpendicular to the floor ofthe feed hopper, Y

2. means adjacent the lower end of the hopper adapted to transfer oneenvelope at a time to said conveyor means,

3. means comprising at least one movable endless belt, forming saidfloor of the feed hopper, and

4. means for sensing the angular departure of the stack from said normalposition and wherein the lower edges of the envelopes lag the upperedges, the sensing means adapted to operate the belt means and move saidlower edges until the stack is restored to its proper position foroptimum pick-up by the vacuum transfer wheels.

2. Apparatus for forming a continuous assembly of envelopes inoverlapping, interconnected form, each envelope having removableperforate margins and a leading and trailing portion, comprising,

a. an endless conveyor for continuously moving the envelopes inpredetermined spaced relationship in a series,

b. a pair of continuously rotatable wheels for applying adhesivematerial of desired length to the enve lope margins in their areas ofoverlap and operated in synchronism with said endless conveyor,

c. each of said wheels having at least one arcuate peripheral portion onwhich the adhesive is deposited for transfer to a margin, the remainderof the periphery being constructed to remain out of contact with amargin, whereby it is ineffective to transfer adhesive to a margin, and

d. means for varying the phase relationship of the arcuate portion withrespect to the movement of the endless conveyor through one increment ofits movement, whereby a desired portion of an arcuate peripheral portionis employed to apply adhesive, to thereby apply a strip of adhesive of adesired length in accordance with the length of the overlap of theenvelope margins.

3. Apparatus in accordance with claim 2 wherein the means for varyingthe phase relationship comprises a clutch interconnecting said wheelswith the conveyor drive means, and means for locking said clutch invarious angular phase relationships to vary the effective length of theadhesive applying peripheral portion.

4. Apparatus for forming a continuous assembly of envelopes ininterconnected form, each envelope having removable margins and aleading and trailing portion, comprising;

a. an endless conveyor for continuously moving the envelopes inpredetermined spaced relationship in a series,

b. a pair of continuously rotatable wheels for applying adhesivematerial of desired length to the envelope margins and operated insynchronism with said endless conveyor, and

c. a movable hold-down member associated with each wheel adapted to movebetween an operative position, at which it distorts an envelope margininto contact with a wheel, and an inoperative position at which a marginmay pass beneath same without being distorted into contact with a wheel.

5. Apparatus in accordance with claim 4 including means for moving thehold-down members to inoperative position, whereby a first envelope of aseries may pass beneath same without application of adhesive theretos 6.Apparatus for forming a continuous assembly of envelopes in overlapping,interconnected form, each envelope having removable margins and aleading and trailing portion, comprising;

a. an endless conveyor for continuously moving the envelopes inpredetermined spaced relationship in a series,

b. means for applying adhesive of desired length to the envelope marginsin their areas of overlap and during their spaced movement along theendless conveyor,

c. said endless conveyor being disposed to transport the envelopes alongan inclined plane at a first speed, l

d. a pair of cooperating driven rolls at the end of the endless conveyorbetween which the envelopes pass and continue movement along theinclined plane,

e. a second station including means adjacent said end for supporting theenvelopes for movement along a horizontal plane, including means forpositively moving the-assembled envelopes at a continuous but lessersecond speed than the linear first speed of said endless conveyor anddriven rolls, so that when an envelope is released from saiddriven rollsvarious heights.

8. Apparatus in accordance with claim 6 including means for feedingreinforcing tapes to the margins at the point where the envelopes enterthe pinch rolls, said means for applying adhesive being so arranged toapply adhesive to the margins throughout their entire heights.

9. Apparatus in accordance with claim 6 including means for feeding acarrier web having perforations adjacent its edges to the margins at apoint where the envelopes enter the pinch rolls, said means for applyingadhesive being so arranged to apply adhesive to the margins throughouttheir entire heights.

1. Apparatus for forming a continuous assembly of envelopes in interconnected form, each envelope having removable margins and a leading and trailing portion, comprising: a. an endless conveyor for continuously moving the envelopes in predetermined spaced relationship in a series, b. means for applying adhesive material of desired length to the envelope margins during their spaced movement along the endless conveyor, c. means for subsequently securing said envelopes together with the previously applied adhesive, and d. an upstream feed station for said endless conveyor comprising;
 1. a feed hopper upon which a stack of envelopes is adapted to rest on their lower edges and normally in a plane perpendicular to the floor of the feed hopper,
 2. means adjacent the lower end of the hopper adapted to transfer one envelope at a time to said conveyor means,
 3. means comprising at least one movable endless belt, forming said floor of the feed hopper, and
 4. means for sensing the angular departure of the stack from said normal position and wherein the lower edges of the envelopes lag the upper edges, the sensing means adapted to operate the belt means and move said lower edges until the stack is restored to its proper position for optimum pick-up by the vacuum transfer wheels.
 2. means adjacent the lower end of the hopper adapted to transfer one envelope at a time to said conveyor means,
 2. Apparatus for forming a continuous assembly of envelopes in overlapping, interconnected form, each envelope having removable perforate margins and a leading and trailing portion, comprising; a. an endless conveyor for continuously moving the envelopes in predetermined spaced relationship in a series, b. a pair of continuously rotatable wheels for applying adhesive material of desired length to the envelope margins in their areas of overlap and operated in synchronism with said endless conveyor, c. each of said wheels having at least one arcuate peripheral portion on which the adhesive is deposited for transfer to a margin, the remainder of the periphery being constructed to remain out of contact with a margin, whereby it is ineffective to transfer adhesive to a margin, and d. means for varying the phase relationship of the arcuate portion with respect to the movement of the endless conveyor through one increment of its movement, whereby a desired portion of an arcuate peripheral portion is employed to apply adhesive, to thereby apply a strip of adhesive of a desired length in accordance with the length of the overlap of the envelope margins.
 3. Apparatus in accordance with claim 2 wherein the means for varying the phase relationship comprises a clutch interconnecting said wheels with the conveyor drive means, and means for locking said clutch in various angular phase relationships to vary the effective length of the adhesive applying peripheral portion.
 3. means comprising at least one movable endless belt, forming said floor of the feed hopper, and
 4. means for sensing the angular departure of the stack from said normal position and wherein the lower edges of the envelopes lag the upper edges, the sensing means adapted to operate the belt means and move said lower edges until the stack is restored to its proper position for optimum pick-up by the vacuum transfer wheels.
 4. Apparatus for forming a continuous assembly of envelopes in interconnected form, each envelope having removable margins and a leading and trailing portion, comprising; a. an endless conveyor for continuously moving the envelopes in predetermined spaced relationship in a series, b. a pair of continuously rotatable wheels for applying adhesive material of desired length to the envelope margins and operated in synchronism with said endless conveyor, and c. a movable hold-down member associated with each wheel adapted to move between an operative position, at which it distorts an envelope margin into contact with a wheel, and an inoperative position at which a margin may pass beneath same without being distorted into contact with a wheel.
 5. Apparatus in accordance with claim 4 including means for moving the hold-down members to inoperative position, whereby a first envelope of a series may pass beneath same without application of adhesive thereto.
 6. Apparatus for forming a continuous assembly of envelopes in overlapping, interconnected form, each envelope having removable margins and a leading and trailing portion, comprising; a. an endless conveyor for continuously moving the envelopes in predetermined spaced relationship in a series, b. means for applying adhesive of desired length to the envelope margins in their areas of overlap and during their spaced movement along the endless conveyor, c. said endless conveyor being disposed to transport the envelopes along an inclined plane at a first speed, d. a pair of cooperating driven rolls at the end of the endless conveyor between which the envelopes pass and continue movement along the inclined plane, e. a second station including mEans adjacent said end for supporting the envelopes for movement along a horizontal plane, including means for positively moving the assembled envelopes at a continuous but lesser second speed than the linear first speed of said endless conveyor and driven rolls, so that when an envelope is released from said driven rolls its leading portion is disposed above and falls onto the trailing portion of the envelope ahead of same in overlapped relationship, and f. a pair of adhesive pinch rolls disposed at the entrance to said second station, for applying pressure to the overlapped envelopes to adhesively attach them to each other.
 7. Apparatus in accordance with claim 6 wherein said pinch rolls are adjustable in a longitudinal direction to thereby dispose the nip of same at various distances from said driven rolls for accommodating envelopes of various heights.
 8. Apparatus in accordance with claim 6 including means for feeding reinforcing tapes to the margins at the point where the envelopes enter the pinch rolls, said means for applying adhesive being so arranged to apply adhesive to the margins throughout their entire heights.
 9. Apparatus in accordance with claim 6 including means for feeding a carrier web having perforations adjacent its edges to the margins at a point where the envelopes enter the pinch rolls, said means for applying adhesive being so arranged to apply adhesive to the margins throughout their entire heights. 